Gear shift and clutch control apparatus



Feb. 10, 1942 K. 'MAYBACH 2,272,571

GEAR sum AND cLuTcn CONTROL APPARATUS Filed May 25, 1937 Mlle/72 0) ffar/ Nqjbad;

Patented Feb. 10, 1942 UNITED STATES PATENT OFF-ICE I 2,272,571 GEAR SHIFT AND CLUTCH CONTROL APPARATU Karl Maybach, Friedrichshaien, Bodensee, Germany, assignor to Maybach-Motorenbau G.' in. b. H., Friedrichshafen, Bodensee,'Germany Application May 25, 1937, Serial N0. 144,719

' In Germany May 30, 1936 (Gina-.01)

18 Claims.

' the course of shifting it is proposed to cause the parts of the transmission to'be connected to produce the new gear selection and which are rotating at different relative speeds to become equalized, or more nearly so, in order that the shifting mechanism may readily effect final driving connection between the parts.

One of the main features of the invention is directed to the speeding up of a slower running part of the transmission preparatory to the bringing about its driving connection with a faster running part. This is accomplished through momentarily, at an intermediate stage of the shifting operation, engaging the main vehicle clutch and causing the vehicle motor to accelerate the slower rotating part. Automatic actuating and control mechanism operating in dependency on the-gear shifting mechanism is provided for both manipulating the clutch and speeding up the motor during the change from one gear selectlontoanother.

The clutch operating mechanism may be of the type already known, which serves to automatically disengage the clutch as soon as the motor comes to an idling speed, and which reengages the clutch as soon as the motor speed is increased by depressing the gas pedal. In utilizing such an automatic clutch mechanism in carrying out the purpose of the present invention arrangement is madeto operate the same momentarily in the course of shifting gears under control of the gear shifting mechanism instead of through the gas pedal, as more fully hereafter explained.

While not limited in its application the present invention has particular utility in connection with constant meshing gear transmissions wherein clutches are employed to produce the diflerent gear selections. The single figure of the drawing is a substantially diagrammatic view illustrating a preferred adaptation of the present invention in connection with such a transmission.

The transmission is generally designated by the numeral 45. A portion of the casing is broken away to illustrate constantly meshing gear 65, 66 and 61, 68 thereof. The portion of the transmission shown is sufllciently illustrative for purposes of the present invention, and it will be understood that the transmission may be of conventional type and constructed to produce two, three or more different speed selections. In order to alternately connect the respective gears 65 and 68 with shaft H5, driven from the motor through the clutch shortly to be described, a

- double claw sleeve 14 is slidably splined on the grooved part I3 of shaft H5 intermediate the two gears. Gear 65 is provided with clutch teeth 69 adapted to mesh with the opposing teeth I0 on the sleeve, and gear 68 is provided with similar teeth 12 adapted to clutch with teeth II of the sleeve. In the alternate left and right positions of sleeve It, gears 65 and 66 are respectively clutched to shaft H5 to provide two different gear selections.

The crank shaft of the motor is indicated at III, and to this is secured the fly wheel I66 through a hub I I0. Clutch disc H2 is supported by a hub H3 slidably splined on keys H4 of shaft H5 leading to the transmission. Mounted slidably in fly wheel I09 to act on the clutch disc is a, pressure plate H6 which is guided for axial movement through projections H1 in slots H8 of the periphery of the fly wheel. Pins I I9 project rearwardly from the pressure plate through the wheel flange I26, and at the outer ends of the pins are provided heads I2I engaged by' arms I22 pivotally supported at I23 on the flange I26. A sliding clutch sleeve 124 is splined to shaft H5 which on movement to the left causes arms I22 acting through pins, H9 to release the pressure plate H6 against action of springs I25 and effect disengagement of the clutch. In the right hand position of sleeve I24 springs I25 cause engagement of the clutch, all as is familiar in the art. A clutch pedal I01 operating through lever I08 may be provided for manually disengaging and engaging the clutch, although automatic mechanism for this purpose is employed incident to the present invention.

The gear shifting mechanism is of the fluid pressure type utilizing servo motors which are selectively controlled through a manual selector mechanism. The system illustrated is of the vacuum type operating from the. suction in the intake manifold of the engine. To accomplish the shifting operation between the respective pairs of gears 65, 66 and 61, 68 of the transmission use is made of a double acting servo motor having a cylinder 46in which moves a piston 41 carried by piston rod 52. The latter is connected with the pivoted lever 62 and acts there- .vh llgh to cause the double claw sleeve I4 to alternately connect gears 65 and 68, through the respective clutches 59 and I2 to shaft II5.

Operating pressure for the shifting motor is supplied through the suction line 28 connecting with the intake manifold 5 of the motor which connects with port 25 and therethrough with chamber 20 of a control mechanism housing 8. From chamber 20 the operating pressure is transmitted through passage 24 to a gear selector valve 28 adjustable, for example, by means of a manually operated wheel 21. In the valve is a passage or groove 29 communicating with passage 24 and through which, in its different adjusted positions, the operating pressure is selectively transmitted through one or another of a series of supply lines connecting with the various gear shifting motors. Also located in valve 28 is a port 35 adapted to register with one or another of the shifting motor supply lines and vent the same through port 31 in the valve casing 38. In the position i of the valve shown, suction is transmitted through groove 29 to line 30 connecting with the right end of cylinder 46 of the particular servomotor shown. Line 34 connecting with the left end of cylinder 46 at the same time is vented to the atmosphere through ports 35 and 31. Under such conditions atmospheric pressure prevails in the cylinder on the left side of the piston while suction is applied at the right end of the piston. The piston with its rod 52 is shown in the course of movement to the right, at which time through lever 62 the double acting clutch sleeve I4 is moving to the left. Clutch teeth I0 of the sleeve are ready to engage teeth 88 of gear 55.

By rotating valve 28 the condition in the pair of lines 30 and 34 connecting with the opposite ends of the cylinder 48 may be reversed so that suction is supplied from passage 24 through line 34, while line 30 is vented to the atmosphere. Under such conditions piston 41 would be caused to move from its right to its left position to produce clutching engagement between sleeve I4 and teeth I2 of gear 68. Thus through manipulation of valve 28 the two difierent gear selections may be alternately obtained through the double acting piston 41.

In addition to the pair of lines 30 and 34 ad ditional lines 3I, 32' and 33 are indicated as being controlled by valve 28. It will be understood that such lines will connect with other servomotors (not shown) which would control other clutches of the transmission 45.

In connection with the gear shifting mechanism just described it is proposed under the invention to more or less equalize the speed of the parts of the transmission in the course of the shifting operation, and to accomplish this by manipula-. tion of the main vehicle clutch. Gas pedal 2 subject to the action of a spring I is connected through a spring compensating device 3 with throttle valve 4 of the carburetor of the vehicle motor, and is also connected with a second lever speed of the motor lever 8 is in the left-end position shown limited against further movement to the left by stop I. Lever 8 acts against the right end of a'pin 9 slidable in the control mechanism housing 8, and upon depression of the gas lever pin 9 is moved to the right. On the left hand portion of pin 9 is a flange I l, and within the pin is a longitudinal bore I2 extending from its left end and communicating with a radial bore I3. When pin 9 is moved to the right under action of its spring I0 upon depressing the gas pedal bore I3 is brought in registry with annular groove I5 provided in housing 8 and connecting through port I4, with the atmosphere.

The left hand portion of pin 9 extends into chamber I8, and in its left end position with the gas pedal retracted to idling position acts through its flange II against the end of a valve body I8 in the suction chamber 20. As shown in the drawing flange II serves to raise valve body I8 from its seat I9 to provide open communication between chambers I6 and 20. Valve body I8 is acted upon by a spring 23.

Formed'within valve body I 8 is a chamber 2| wherein is located a valve 22 forced by the pressure of a spring 23 against the end of pin 9. If

desired for purposes hereafter explained, valve 22 may be provided with a small port I29.

From chamber I6 extends a passage 89 leading into chamber 81, and thence through the adjoining chamber 83 to passage I00. The latter connects with a supply pipe I02 which leads to the chamber I04 to the right of piston I03 in the cylinder ml of a servo motor for actuating the main vehicle clutch heretofore described. Piston I03 is acted upon by spring I05, and is provided with a piston rod I08 connecting with the clutch actuating lever I08 which serves to move the clutch sleeve I24. When piston I03 is held by spring I05 in its left end position the clutch is engaged, and when suction is applied through line I02 to move piston I 03 to its right end position the clutch is disengaged.

The clutch operating mechanism, to the extent so far described, will function in dependency on the gas pedal 2. When the pedal is in retracted position as shown in the drawing pin 9 is in its left hand position under the action of spring I operating through lever 8. Flange II on pin 8 holds valve body I8 on its seat I9 allowing suction from pipe 26 to pass from chamber 20 through chamber I8, through passage 89, and eventually through line I02 to move piston I03 of the clutch servomotor to the right and cause the clutch to release. on the other hand, when the gas pedal 2 is depressed pin 9 under action of its spring I0 moves to the right, allowing valve body I8 to engage its seat I9 and thus cutting off communication between the suction in chamber 20 and chamber l6. Pin 9 continues to move to the right, releasing flange II from engagement with valve body I8 and establishing communication between chamber I8 and chamber H. The radial port I3 in pin 9 is brought into registry with groove I5 to establish communication through port I4 between bore I2 of the pin and the outer air. During movement of pin 9 to the right as flange II moves through chamber IS the compression on spring 23 in chamber 2| becomes less so as to allow valve 22 to unseat. Atmospheric pressure from the outside thence passw through bore I2, chamber 2|, chamber I5, passage 89, and eventually through line I02 to vent chamber I04 of the clutch servomotor. Piston I03 is then caused to move to its left end position under action of its spring I05 to effect engage ment of the clutch.

Arrangement is made in connectionvwith the clutch operating mechanism to cause the clutch to be partially engaged during operation of the gear shifting mechanism in dependency on the latter without operation of the gas pedal 2, and further arrangement is made so that at the same time the vehicle motor may be speeded up, also independently of the gas pedal, so that the slower running part of the gear transmission may be accelerated to facilitate its engagement with the part with which it is to be connected in producing a new gear selection under operation of the gear shifting motor, all as now to be described.

A cylinder having therein a piston or a diaphragm 16 operates through a rod system TI to open throttle valve 4 of the carburetor. When member I6 moves to the right the throttle valve is opened and through the provision of the compensating device 3 this is accomplished without disturbing the released position of gas pedal 2 or causing any movement of pin 9, and the other parts of the clutch system. An operating suction is transmitted to cylinder I5 to produce this action from supply line 38 communicating with the right end of the gear shifting motor cylinder 46. Branching oiT from line 38 is a line 48 connecting with port 58 in the right hand guide por-'- tion of cylinder 46, and a corresponding line 56 transmits the suction therefrom to line 55. Located in the piston rod 52 is an annular groove 53 which in the position shown establishes communication between lines 48 and 56. In such position, as previously explained, suction is being applied through line 38 to the right hand end of cylvehicle motor to be transmitted through shaft I I5 to effect the speeding up of the clutch sleeve I4 preparatory to final engagement thereof with the teeth of gear 65, special mechanism is provided in the control housing 8 responsive to operation of the gear shifting motor to quickly partially engage the main vehicle clutch, and then to immediately release the same after the gear shifting motor has brought the gear clutch parts in the transmission into final engagement.

Located in chamber 83 in housing 8 is a double acting valve 84 which in its right end position engages a seat 85 to cut ofi communication between chamber 83 and chamber 81. When valve 84 is moved to such position suction transmitted through chambers 28 and I6, passage 89, and

chamber 81 is cut oil from the supply line I82 of the main clutch servomotor. Except during operation of the gear shifting motor 46 valve 84 is urged through a spring at its right end against its left hand valve seat 86, and under svich conditions communication is maintained between suction line 89 and clutch motor supply line I82 through chambers 81 and 83. Valve 84 is provided with a pin 8| extending through a bore into chamber 88 of the housing 8 in which is located a piston 82. Connecting. with chamber 88 is a second branch of suction line 55, the first branch of which communicates with cylinder 15. With the position of piston 41 and rod 52 of the gear shifting motor shown in the drawing suction from line 38 will be supplied through the intermediate lines 48 and 56, and the respective branches of line 55 simultaneously to cylinder I5 which serves to speed up the vehicle motor and to chamber 88 whose piston 82 acts upon pin 8| to shift valve 84 against its right end seat 85.

The movement of valve 84 from its left seat 86 to its right seat 85 establishes communication thereof. From chamber 88 extends a passage 98 opening into a further chamber M. In chamber 9| is located a valve 93 engageable with a seat 95. A smallchamber 91 behind the valve has a port 96 opening to the atmosphere. Valve 93 is held in engagement with its seat by a spring 92 adjustable through a screw tensioning member 94. By reason of the partial vacuum created in chamber 9i when the same is put into communication with chamber and the clutch motor supply line I82, difference in pressure exists on the two sides of valve 99 in the chambers 9| and 91 and the valve is caused to open against the tension of its spring allowing chamber I84 of the clutch motor to be vented by reason of the communication then existing between line I82, chamber 89, chamber 86, passage 98, chamber 9|, chamber 9?, and port 96. When the pressures on the opposite sides of valve 93 have been partially equalized to an extent dependent upon the tensioning adjustment of spring 92 the valve is caused to close. By adjustment of member 94 it is possible to regulate the extent to which the vacuum condition is reduced in chamber I84 of the clutch motor. In carrying out the purposes of the invention the adjustment will be such that the suction in the clutch motor chamber is only partially vented. Piston I83 will move to the left only sufliciently to produce a light engagement between the parts of the main clutch. As soon as the clutch has been so engaged shaft II5 will be driven by shaft II I, and since the vehicle motor has been speeded up clutch sleeve I4 on shaft II 5 will be accelerated until its speed is sufiicient to enable the teeth I8 to be brought into final engagement with teeth 69 of the originally faster moving transmission gear 65. As soon as cornplete engagement has been brought about piston 41 of the gear shifting motor will move to its final right end position under the suction existing in line 38. The corresponding movement of piston rod 52 will move groove 58 therein into registry with line 56 and vent 68. The two branches of line 55 connecting with line 56 will thereupon be immediately vented through port 68. Member 16 in cylinder I5 will thereupon move to the left to release throttle valve 4, and cause the vehicle motor to slow down, and at the same time the venting of chamber 88 through the second branch in line 55 will enable the spring to the right of the valve 84 to cause the valve, its pin 8| and piston 82 to be moved to their left end position. As soon as valve 84 is moved into engagement with its left seat 88, chamber 88, passage 98 and the venting valve 93 will be cut off from communication with chamber 83. Suction 'will then again be transmitted to chamber 83 through passage 89 and chamber 81 and be applied to the clutch motor through line I82 so as to cause the clutch to again release.

It will be understood that during operation of valve 93 the vehicle clutch parts are engaged only sufllciently to speed up the clutch sleeve I4 in the transmission and that as soon as the clutch sleeve has been moved into final engagement with the corresponding clutch half of the gear the vehicle clutch parts will slip relative to each other. If the main clutch were completely engaged when the gear shifting had been completed motor shaft III would continue to drive shaft H5, and cause a shock on the operating parts and jerking of the vehicle since a complete drive would exist between the motor and the vehicle wheels. As previously indicated the extent to which the clutch parts are caused to engage and still provide th desired slipping action under these conditions will be determined by adjustment of spring 92 of valve 93.

When utilizing the spring tension valve 93 to eifect partial venting of the clutch motor and the corresponding partial engagement of the vehicle clutch, chamber 9| which houses valve 93 can be made relatively small. The employment of valve 93 to control port 96 is not entirely necessary.

In addition to the mechanism for speeding up a slower running part of the transmission, I

have also indicated diagrammatically a brake apparatus I30 for slowing down a faster moving transmission part preparatory to connecting the same to a slower moving part. Such braking apparatus will likewise be controlled by the gear shifting motor so as to operate at an intermediate stage of the movement of the gear shifting motor piston "when suction is supplied on the left side thereof through lin 34. Line 49 branches off line 34 and connects with a port 5| in the left end portion of cylinder 46. Groove 54 in piston "rod 52 is brought opposite line 49 and suction is thereby established in line 51 to cause the latter to exercise a braking action on the faster moving transmission part. After the transmission parts have been brought into final engagement through movement of piston 41 into its left end position groove 59 in piston rod 52 vents line 51 through port 6| to releas the braking apparatus I30.

The operation of the embodiment of the invention above described in detail will now be summarized.

'During travel of the vehicle the main clutch will be engaged and some'gear selection of the transmission will be connected therein. The accelerator pedal will be in som depressed position. The gas pedal may be raised or lowered to vary the vehicle speed without moving pin 9 since lever 6 connecting with the gas pedal engages pin 9 only when the gas pedal is im'the last stage of movement to its idling position.

As the pedal is released pin 9 is moved to the left raising valve I8 from its seat I and allowing operating pressure, that is suction, from line 26 and chamber 20 to be supplied through chamber l6, line 89 and chamber 81.

At this time valve 84 is held in its leftposition against seat 86 by its spring. The suction accordingly passes on through chamber 83 through line I02 to chamber I04, causing the clutch motor piston I03 to move to the right and fully release the main clutch.

If no gear selection is set through adjustment of gear selection valve 28, valve 84 remains in its left position, and the vehicle clutch is held released, in freewheeling, until the gas pedal is again depressed to speed up the motor. when the latter is don pin 9 moves to the right under actionof-its spring I0, venting bore l2 through port I3, groove I and port I4. During movement of pin 9 to the right valve I8 is brought into engagement with its seat l9, thereby cutting off suction in the chamber from chamber I0. When valve l8 has reached its seat I9, but before pin 9 has reached its right end position a pressure differential exists on opposite sides of valve 22 since bore I2 is now vented to the atmosphere, but suction still exists in chamber 2| and in the other parts of the system. Valve 22 is therefore moved to .the left against action of its spring 23, allowing the suction prevailing in chamber I0, lin 89 and the other communicating parts to be partially reduced until the pressure acting on the opposit sides of the valve 22 are balanced by the force of spring 23. At that time valve 22 again closes under the action of its spring. As a result of the partial venting clutch motor piston I03 is moved part way to the left under action of its spring I05, and the clutch begins to engage. Even without any further venting through valve 22 piston I03 will continue to move gradually to th left through ordinary leakage around such piston and the clutch will gradually be brough into fully engaged position. By reason of such gradual connection of the clutch driving engagement between the motor and the vehicle wheels is brought about without shock. In this connection it is furthermore pointed out that during the final movement of pin 9 towards its right end position the tension on spring 23 acting on valve 22 is gradually decreased as the gas pedal is depressed from its idling position. Hence. by suitable manipulation of the gas pedal and corresponding variation in the tension of spring 23 the operation of valve 22 can be somewhat controlled so that the flow of air past valve 22 can be made faster or slower, and accordingly venting of the main clutch motor and reengagement or the clutch will occur more or less slowly. If it is found that the clutch operates too slowly a small throttle bore I29, heretofore referred to, may be provided in valve 22 to accelerate the clutch action.

' is again depressed. Assuming that suction exists in the clutch motor so that the latter is fully released, the setting of the gear selection causes suction from chamber 20 to be transmitted through bore 24 and groove 29 to a gear shifting motor. which will be assumed to be the one, 48, here illustrated. Further assuming that clutch sleeve 14 through its teeth II has been in driving engagement through teeth 12 with gear 13, the application of suction "through line 30 will cause piston 41 to move part way to the right at which time the opposite teeth I0 make preliminary engagement with teeth 69 of gear 65. At this stage groove 53 in piston rod 52 is in the position shown in the drawing and suction from line 30 is transmitted to the two branches of line 55. The vehicle motor is speeded up through partial opening of throttle valve 4 under action of member 16 in cylinder 15. At the same time suction causes piston 82 in chamber to move to the right, whereby through pin 8| valve 84 is moved against its right seat 85 to cut off the supply of suction to the main clutch motor. The clutch motor is then partially vented through port and the action of the valve 93 to momentarily bring the main clutch into light engagement. Shaft H5 is accordingly caused to rotate at a. higher speed, and its sleeve 14 is accelerated until the teeth 10 and as are incondition to be brought into flnal complete engagement. Piston 41 01' the gear shifting motor moves to its right end to bring about such flnal engagement. Through the corresponding final movement of piston rod 52 to the right suction is cut off from cylinder 15 and chamber 80, and these are immediately vented through lines 55 and 56, groove 00 and port '60. The carburetor throttle valve 4 is moved to slow down the motor, and valve 84 is moved to its left end position by its spring. Suction is reestablished through chambers; 81 and 83 to line I02, and piston I03 of the clutch motor moves to its right end position to fully release the main clutch. When after the gear shifting operation has been eifected in the manner just described the gas pedal is depressed, pin 9 will assume its right end position and the main clutch will be engaged by venting of the clutch motor through ports I 3 and M in the manner heretofore described.

From the description here given it will be understood that the essential function of valve 84 is to render inoperative the normal control mechanism of the main clutch motor, and to provide for the control thereof by the gear shifting mechanism momentarily during shifting from one gear selection to another. Valve 93 functions to regulate the degree of engagement of the clutch at such time. Valves I8 and 22 operate alternately under control of the gas pedal to effectv disengagement and engagement of the vehicle clutch, and such parts are positioned so as to be rendered inoperative under control of valve 84.

The invention is not to be taken as limited to the particular fluid pressure system and detailed arrangement of operating parts shown, but is to be measured by the scope of the appended claims.

I claim:

1. In a motor driven vehicle having a clutch and a variable speed gear transmission, fluid pressure operated gear shift means for the transmission, fluid pressure operated means for actuating the vehicle clutch, and ,control means for the clutch actuating means responsive to the gear shifting means to effect actuation of the clutch during shifting action of the gear shift means.

2. In a motor driven vehicle having a clutch and a variable speed gear transmission, a motor for shifting the transmission gears to diflerent speed selections, a motor for actuating the vehicle clutch, and control means for the clutch motor operating in dependency on the gear shift motor to cause the clutch motor to briefly engage and then disengage the vehicle clutch interme the vehicle clutch and means for speeding up the vehicle motor.

4. In a motor driven vehicle having a clutch and a variable speed gear transmission, power operated gear shift means for shifting the transmission parts to different gear selections, and mechanism controlled by the gear shift'means operative toaccelerate a slower running'transmission part during operation of the shift meansto bring about engagement of said slower running part with a faster moving transmission part, said mechanism including means for momentarily engaging and then disengaging the vehicle clutch,

and means for speeding up the vehicle motor during said momentary engagement of the clutch.

5. In a motor driven vehicle having a clutch and a variable speed gear transmission, power operated gear shift means forthe transmission, actuating means operative to engage and then disengage the vehicle clutch during the period of shifting from one gear selection to another,-

means for changing the speed of the vehicle motor, and control means for both said clutch actuating means and said motor speed increasing means operating in dependency on said gear shift means.

6. In a motor driven vehicle having a clutch and a variable speed gear transmission, a servo motor gear shift for the transmission, a servo motor operator for the vehicle clutch, control means for the vehicle clutch motor working in dependency on the gear shift motor, said control means being operative during shifting of a slower running part and a faster running part of the transmission into driving connection to cause the vehicle clutch momentarily to engage, and also being operative when said transmission parts have been connected to cause the vehicle clutch to disengage, and means operative during said shifting operation to cause the vehicle motor to speed up while the clutch is momentarily engaged so as to accelerate the slower running transmission part preparatory to its. connection with the originally faster running transmission part.

able speed gear transmission, a servo motor gear shift for the transmission, a gas control for the vehicle motor, a motor for the vehicle clutch normally controlled by the gas control, and means operating independently of the gas control for causing the clutch motor to operate in deand further control means for the clutch motor independent of said first control means and. be-

ing responsive to the gear shift motor during shifting action thereof to bring about driving connection between a slower running part and a faster running part of the transmission.

9. In a motor driven vehicle having a clutch,

a fluid pressure clutch actuating motor, a variable speed gear transmission and a power operated gear shift motor for the transmission, means controlled by the gear shift motor during shifting movement thereof for adjusting the op'erating pressure of the clutch motor to effect partial but incomplete engagement of the clutch.

10. In a motor' driven vehicle having a clutch,

a fluid pressure clutch'actuating motor, a variated gear shift motor for the transmission, means -for causing the vehicle motor to accelerate a slower running transmission part during shifting action of the gear shift motor to bring about driving connection between said,slower running part and a faster runningtransmission part, means responsive to the gear shift motor controlling the operating pressure of the clutch motor during said shifting operatiomand a second control means operating independently of the gearshift motor controlling operation of the clutchmotor at times other than during shifting action of the ear shift motor. a

7. In a motor driven vehicle, a clutch, a vari- 11. In a motor driven vehicle, a variable speed geartransmission, a power operated gear shift motor for the transmission, a clutch, a fluid pressure clutch operating motor, a fluid pressure supply system for the clutch motor, means for causing the vehicle motor to speed up during shifting into connection of a slower running part and a faster running part of the transmission, and a control member in the clutch motor supply system operating in dependency on the gear shift motor to control the supply of operating pressure to the clutch motor and effect momentary engagement of the clutch during shifting of the slower running and faster running transmission parts into connection.

12. In a motor driven vehicle, a variable speed gear transmission, a power operated gear shift motor for the transmission, a clutch, a fluid pressure clutch operating motor, a fluid pressure supply system for the clutch motor, means for causing the vehicle motor to speed up during shifting into connection of a slower running part and a faster running part of the transmission, and a control member in the clutch motor supply system operating in dependency on the gear shift motor to control the supply of operating pressure to the clutch motor and effect momentary engagement of the clutch during shifting of the slower running and faster running transmission parts into connection, said control member operating upon completion of the connection between said transmission parts to restore the supply of operating pressure to the clutch motor and causing the clutch to be disengaged.

13. In a motor driven vehicle, a variable speed gear transmission, a power operated gear shift 15. In a motor driven vehicle, a variable speed gear transmission, a power operated gear shift motor for the transmission, a clutch, a fluid and a faster running part of the transmission,

motor for the transmission, a clutch, a fluid pressure clutch operating motor, a fluid pressure supply system for the clutch motor, means for causing the vehicle motor to speed up during shifting into connection of a slower running part and a faster running part of the transmission, a control member in the clutch motor supply system operating in dependency on the gear shift motor to control the supply of operating pressure to the clutch motor during shifting of a slower running transmission part into connection with a faster running transmission part, and means coactive with said control member to reduce the operating pressure previously acting on the clutch motor so that said motor operates to effect engagement of the clutch during said shifting operation.

14. In a motor driven vehicle, a variable speed gear transmission, a power operated gear shift motor for the transmission, a clutch, a fluid pressure clutch operating motor, a fluid pressure supply system for the clutch motor, means for-causing the vehicle motor to speed up during shifting into connection of a slower running part and a faster running part of the transmission, control valve means in the clutch motor supply system operating in dependency on a lever controlling the vehicle, said means controlling the admission of operating pressure to the clutch motor and the release of operating pressure from said motor, and a control member in the supply system beyond said control valve means operating in dependency on the gear shift motor to control the supply of operating pressure to the clutch motor and effect momentary engagement of the clutch during shifting of the slower running and faster running transmission parts into connection.

control valve means in the clutch motor supply system operating in dependency on a control lever of the vehicle, said means .controlling the admission of operating pressure to the clutch and the release of operating pressure from said motor, a control member in the clutch supply system beyond said control valve means operating in dependency on the gear shift motor to control the supply of operating pressure from the clutch motor during shifting of a slower running transmission part into connection with a faster running transmission part, and means coactive with said control member to reduce the operating pressure previously acting on the clutch motor so that said motor operates to effect engagement of the clutch during said shifting operation.

16. In a motor driven vehicle, a clutch, a motor for engaging and disengaging the clutch, a variable speed gear transmission driven by the vehicle motor through said clutch, clutch means in said transmission for engaging and disengaging different gear selections, shift means for said transmission clutches, and control-means'ior the vehicle clutch motor operating in dependency on the shift means, said control means being operated by the shift means after the latter has disengaged one transmission clutch to release a previous gear selection to actuate the vehicle clutch motor to effect engagement of the vehicle clutch and drive the transmission by the vehicle motor, and said control means being again operated by the shift means before final engagement of another transmission clutch to produce the next gear selection to cause the vehicle clutch motor to disenga e the vehicle clutch.

1'7. In a motor driven vehicle having a clutch and a variable speed gear transmission, a gas lever controlling the vehicle motor speed, a fluid pressure motor for operating the clutch', a control valve operated by the gas lever controlling the supply of operating pressure to the clutch motor, means for shifting the transmission gears to different speed selections, and a second pressure control valve also controlling the supply of operating pressure to the clutch motor, and actuating means for closing and opening the second pressure control valve controlled by the operation of the gear shift means.

18. In a motor driven vehicle having a clutch and a variable speed transmissio'n,,a source of fluid pressure, a fluid pressure motor for operating the clutch, conduit means connecting said source to said motor, first pressure control valve means in said conduit means operative to control the supply of pressure to the clutch motor, means for shifting the transmission gears to different speed selections, second control valve means in said conduit means operative to cut off the supply of pressure through the conduit means from said source to said motor, and actuating means for operating said second valve means controlled by operation of the gear shiftmg means.

KARL M'AYBACH. 

